Here the Z-Sigil won't affect the set or weapon used.
The weapon of choice is Divine Galatine. The para is incredibly helpful in this fight so Divine Galatine wins over the Thunder evo. I think Very Long also helps a lot in this fight since hitting both at the same time will be key to a fast time.
Sigil 1: [ SnS Up 15 | Beam Slash | Length Up ]
Sigil 2: [ Element 15 | Element 15 | Element 15 ]
Sigil 3: [ Element 15 | Element 15 | Element 15 ] or [ Element 15 | Duration 12 | Wait Time 17 ]
Maybe it would theoretically be possible to run SW with Rush Up, since hitting both will proc it super fast but I wouldn't bother going through hell like that.
Elixir of Peace will add 130 defense which will cause you to survive some attacks but its not technically needed. Use Random Ball's free yourself from any grab attacks.
I use my Z-sigil right at the beginning to make them Nuke as early as possible, The rest of the fight is a lot of just trying to survive. Your highest priority should be to not get grabbed, getting hit by anything else isn't too bad but there are still moves that can oneshot with adren so be aware of those. The best move they can do is their Chin Slam, they will be locked into a quite long animation without a hitbox so you can capitalize or have a short 1v1 with the other one. With the Z-Sigil most of your damage happens during the last 30 seconds of the quest so getting a para there and generally performing well will be key.